Pencil



April 8 ,1924."

H. L. FISCHER PENCIL Filed May 29 1920 Patented Apr. 8, 1924.

UNITED STATES PATENT/OFFICE."

HOWARD L; EISGHER, on ST. neon, MINNESOTA, AssIGN-on To BnbWN a BIGELoW,"

or s'r. PAUL, MINNESOTA; a coRronATIoN or MINNESOTA.

PENCIL. 3

Application filed May 29,

Minnesota,- have invented a new and useful Improvement in Pencils, of which thefollowing is a specification. j

My invention relates to pencils and is part-icularly adapted to the propelling mechanism for the marking lead in position for of this pencil is of a screw type andithe'primary object is in a driven member which is adapted to engage the threads of the propel. ling mechanism under spring tension and to be driven in either direction by the rotation of an operating means 1 A feature of the invention is in providing the propelling mechanism with a lead receiving and driving member which is contained in a tubular threaded member and adapted to engage the threads of thesame under spring tension. In the manufacture of pencils of this nature it is desirable to have the member which is driven by the threads of the propelling mechanism adjustable so as to hold it in close contact with the threads of the tubular threadedmember because of the variation in the gauge of the tubing from which the threaded member is made. A slight variation in the gauge ofthis tubing or'in thethreads formed in the same necessitates the close adjustment of the driven member of the'penc1l and therefore a driven member with IBSlllBllZ IHSRIlS which is adapted to hold the member into engage ment with the threads of the tubular member under spring tension provides'means in the propelling mechanism of the pencil which is self-adjusting to any variations or differences in the threads of the same.

The invention further provides,in the particular construction, means for automatically taking up the wea'r'between the tubular threaded member and the driven member and thus holding the marKmg lead, in writing position in the pencil against any longitudinal movement unless the operating head,

which is adapted to operate the driven member, is rotated. This construction also provides suflicient friction between the threaded member, which in this pencil is held stationary against rotation, and the rotatable operating parts or member which is adapted 1920. Serial No. 385,246.

to rotate the driven member over the threads of the stationary tubular member. I

In the drawings forming part of this sp ci c i n; H, V Figure -1-;is a longitudinal cross section of any pencil, a portion of 'whichyis broken away, illustrating my; improved, propelling mechanism.

Figure 2 is a plan view of the driven member with its lead holding socket of'the pencil. use in the pencil. The propelling mechanism F igure3 illustrates a detail of. aportion of the pencil barrel and propelling mecha- .msm in longitudinal cross section, showing a side elevationof a different form of driven member. 1

Figure 4 is a section on the line H of Figure 3. Y Y i Figure 5 illustrates a geometrical development of the driving member, as it isblanked out from sheet material, showing "the construction illustrated in Figures 3 and 4.

Figure 6 illustrates a plan view of a different form of the driven member of the propelling mechanism. I

Figure 7 illustrates the threaded portion of the member illustrated inQFigure 6. Figure 8 is'an end view of the threaded member illustrated in Figure 7.

Figure 9 is a side elevation of the-member illustrated in Figure ,6, having the threaded plate removed therefrom. The drawings illustrate the body of a penoil A, a portion offthe barrel 10 of which is brok'enaway, The barrel 10 of the pencil is o m d of. ubing having a thin wall witha smoothy nner-contour. a

The propelling mechanism B of the pezioil A is formedof a tubular threaded member 11, which is rigidly attachedto the look ing head or collar 12, formed-with a threaded portion 13 which engages threads formed on the open rear end 14'of the pencilbarrel 10. This construction while the head 12 is allows the tubular threaded member 11 of the r i propelling mechanism to be readily inserted and attached against rotation in the barrel 10 or to be easily removed when. it is desired." I w i The lead'prope'lling mechanism B is provided with through the threaded member, 11 and is .pro-

a tubular operating member 15,

vided witha, longitudinally extending open a slot 16. The tubular operating member 15 is rigidly attached to the operating head 17, which is positioned adjacent to and rotates against the collar 12 at the outer end of the propelling mechanism.

mechanism is supported and engaged by a collar 18 so as to hold the forward or inner end of the tubular threaded member 11 centrally in the barrel 10. The inner end of the tubular operating member 15 extends through the collar 18 a short distance and a locking collar 19 fits closely over the projecting end of the same and is rigidly attached thereto by solder or other suitable means. The operating head 17 forms a shoulder on one end of the tubular member 15, while the collar 19 forms a shoulder on the other end so as to hold the member 15 freely rotatable in the threaded member 11 with the head 17 engaging the collar 12 and the collar 19 engaging the collar 18 to hold the member 15 against longitudinal movement.

The lead propelling mechanism B is provided with a member 20 formed with a thin, flat, central, thread engaging portion 21, which extends through the slot 16 and has spring arms or spring tongues 22 and 23 projecting from the ends of the portion 21 and positioned to engage the inner surface of the tubular operating member 15 so as to hold the portion 21 engaging the threads 2d of the tubular member 11 by the recesses 25 under spring tension to form the driven member of the lead propelling mechanism. A lead receiving socket 26 is formed on the forward spring arm or tongue 23 of the member 20, which is adapted to receive and hold the rear end of the marking lead 27. The spring arms 22 and 23 hold the portion 21 of the member 20 into engagement with the threads of the tubular member 11 under spring tension to take up any ineqnalitiesin the formation of the threads 24: or of the gauge of the tubing forming the member 11 of the propelling mechanism. Thus in the assembling of the propelling mechanism 13 of the pencil A a slight variation in the gauge of the tubing will not interfere with the successful operation of the propelling mechanism, as the spring arms will automatically hold the driven member 20 into close engagement with the threads 24 .and also automatically take up the wear be tween the driven member 20 and the tubular threaded member 11. In this manner a close fit between the driven member 20 and the threaded tubular member 11 is always insured and the marking lead 27 is held firmly in place Wherever it is moved throughout the length of the propelling mechanism B. The spring arms 22 and 23 of the driven member 20 also provide sufficient friction between the driven member, the operating member 15 and the threaded The inner end of the threaded member 11 of the propellingmember 11 to prevent too free rotation be tween the operating parts of the propelling mechanism, a feature in any screw-feed propelling mechanism for pencils. In this manner the spring means of the driven member not only takes up the wear and keeps the parts closely fitting together but provides frictional means for holding the parts together.

The driven member 20 in Figure 3 is formed from a thin sheet ofspring material, which is blanked out into the form illustrated in Figure 5, having a central threaded portion 28 which is formed with threads 29. The portion 28 is comparatively wide so as to give a good, substantial bearing surface for the threads 29 against the threads 2% of the tubular member 11, and the sides of the same project on either side of the slot 16,

as illustrated in Figure l. Spring arms 30 I and 31 are formedprojecting from the threaded portion 28 to perform the same function as the spring arms 22 and 23 in holding the threaded portion 28 against the threads 24 under spring tension during the operation of the propelling mechanism. In this conwhich is desirable struction ears 32 are formed projecting from the sides of the spring arms 30 and 31. The ears 32 are formed in close relation to the threaded portion 28 and are adapted to be bent downward along the dotted lines illustrated in Figure 5 into the positions illustrated in Figures 3 and 4. so as to form wearing surfaces on either side of the arms 30 and 31 which are adapted to engage the slot 16 of the operating member 15 and thus prevent any excessive wear on the sides of the thin spring arms 30 and 31. In this construction the arms 30 and 31 readily hold the threaded portion of the driven member under spring tension against the threads of the threadedmember 11 so as to perform the same functions as the construction illustrated in Figure 1. The member 20 is formed with a lead holding socket 33 on the forward end of the arm 31.

Figure 6 illustrates another form of driven member 20", which is very similar to the member 20, having the identical spring arms 22 and 23 projecting from the flat, thin, central or body portion 21, which projects through the slot 16. The upper edge of the body portion 21 is notched out to form a recess 34:, while stoplugs 35 project upward from each end of the recess. A curved threaded plate 36 is adapted to fit in the recess and is formed with notches 37 on either end, into which the lugs 35 engage to hold the threaded plate 36 in position on the member 20". The member 20 can be used without the plate 36, if desired as the lugs or teeth 35 will engage the complemental threads of the member 11. while the space 34: would allow the threads of the member 11 to be unen aged at this space during the operation the pusher in the pencil. In the assembly of the propelling mechanism B, when the driien member is used the threaded plate 36 is either rigidly attached in the recess 34 or is set freely in place therein and then inserted into the tubular threaded member 11. The spring arms 22 and 23 tend to hold the threaded plate 36 into engagement with the threads 24 of the tubular member 11 under spring tension and thus hold the same in place against disengagement from the notch 34, while the lugs hold the plate against longitudinal or transverse movement in relation to the member 20.

The threads formed in the portion 28 of the member 20 and the plate 36 of the member 20" are adapted to be of substantially the same pitch as the threads 24 of the tubular member 11 so that when either of these members are held in the rotatable member 15, when the propelling mechanism is assembled, by rotating the head 17 the threads of the tubular member 11 will tend to drive the members 20 or 20 in a longitudinal and rotary direction in the propelling mechanism. The threads or notches 25 of the member 20 are spaced apart to conform with the pitch of the threads 24. Thus any of the driven members, when used in the propelling mechanism, are readily operable to propel the marking lead 27, which is held centrally therein in either direction in accordancewith the operation of the head 17 and the tubular member 15.

The wide thread engaging surface of the members 20 and 20" may be preferred in some instances in the propelling mechanism but ordinarly the thread engaging portion of the member 20 is sufiicient to engage the threads 24 by the, aid of the spring arms 23 and 22 to hold the marking lead 27, which is in writing position in the pencil,

against any play or free longitudinal movement 1n the pencil. It 1s of primary 1mportance in this invention to provide the spring means to the driven member, such as the arms 22 and 23, to take u a the wear between the operating parts of the pro- In accordance with the patent statutes I i have described the principles of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the construction shown is only illustrative and that the invention can be carried out by other means and applied to uses other than those above set forth within the scope of the following claims:

1. A lead carrier for screw operated mechanical pencils wherein a. threaded member is adapted to cause the lead carrier to be moved in either direction in the pencil, an arcated plate-like thread engaging portion secured to the lead carrier and resilient means adapted to hold said plate in engagement with said threaded member.

2. A lead carrier including, resilient ends, a body portion between said ends and a removable threaded member adapted to engage in the complemental threads in a. pencil to move said carrier.

3. A lead carrier for a mechanical pencil having resilient ends, an arcated plate-like threaded member positioned between the ends and a lead socket on one of said ends.

HOWARD L. FISCHER. 

